Novel inorganic oxide supported organotin hydrides for fine chemical catalysis

Chemically tethered organotin hydride on various acid pre-treated metal oxi de surfaces has been prepared through reaction of surface hydroxyl groups w ith the hydrostannated product of trimethoxyvinylsilane with dibutyltin dih ydride. It was found that some support oxides, typically hydroxylated silic as, clearly show hydride carrying capacities comparable to the best polymer supported hydrides reported but with expected advantages in mechanical and thermal stability. It is also shown, for the first time, that these oxide- supported hydrides can be used as cleaner and genuine heterogeneous catalys ts. In the presence of sodium borohydride, the depleted hydrides can be reg enerated in situ and complete the catalytic cycle. Therefore, novel heterog eneous catalytic hydrogenation reactions and intramolecular coupling reacti ons using the supported organotin hydride catalyst are demonstrated.